1. Prior to October first, nineteen hundred ninety-two, no permit shall be required for discharges composed entirely of stormwater, except as provided in subdivision two of this section.

2. Subdivision one of this section shall not apply with respect to the following stormwater discharges:

a. A discharge with respect to which a permit has been issued under this title prior to the effective date of this section;

b. A discharge associated with industrial activities directly related to manufacturing, processing, or raw materials storage areas at an industrial plant;

c. A discharge from a municipal separate storm sewer system serving a population of one hundred thousand or more; or

d. A discharge which the commissioner determines contributes to a violation of water quality standards adopted pursuant to section 17-0301 of this article or is a significant contributor of pollutants to the waters of the state.

3. Permits for discharges from municipal storm sewers:

a. May be issued on a system or jurisdiction-wide basis, pursuant to paragraph (a) of subdivision seven of section 70-0117 of this chapter;

b. Shall include a requirement which regulates non-stormwater discharges into the storm sewers; and

c. Shall require controls to reduce the discharge of pollutants to the maximum extent practicable, including management practices, control techniques and system design and engineering methods, and such other provisions as the commissioner determines appropriate for the control of such pollutants.

4. The commissioner shall promulgate regulations setting forth the requirements for permit applications for stormwater discharges and the deadlines for the receipt of applications.